Oil switch



A. F. C. LoTz Jan. 27, 1931.

OIL SWITCH Original Filed Dec. l, 1924 3 Sheets-Sheet l Jan. 27, 1931.A.l F. c. Lo'rz 1,790,275

OIL SWITCH Original Filed Dec. l, -1924 3 Sheets-Sheet 2 mi -i @0 gli f3f@ @im 6 ff 1 JUL 27, 1931- A. F. c. LoTz 1,790,275

OIL SWITCH original Filed nec. 1,1924 3 Sheets-sheet 3' Patented Jan.27, 1931 UNITED ,STATE-s PATENT OFFICE if ALFRED F. C. LOTZ, F CHICAGO,`ILLINOIS, ASSIGNOR T0 ELECTRICAL ENGINEERS EQUIPMENT OOHPANY, 0FCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS on. SWITCH Applicationlled'jDecember 1, 1924, Serial No. 753,028. Renewed October 2, 1930.

This invention relates to improvements in switches of the oil immersedtype. Although special reference has been made to oil switches, theseimprovements ma nevrtheless be embodied in switches o other y es. j

Tt becomes necessary, in switches of this sort, to not only break awaythe contact means from each other quickly. but also to extinguish thearc which is created when the contact is broken. To do this, it isnecessary that the contacts be separated in a quenching medium such asoil, and also that the o 'erating parts not only be light to actquickly, but also be strong enough to withstandl the magnetic andmechanical'stresses to which they are subjected.

Heretofore, it has been necessary to make the contact actuating partsrelatively heavy and massive to stand up under the stresses mentioned.These have also been of rather intricate design and due to theirinertia, it became a diilicult problem to get a quick and positiveseparation of the switch contacts. Furthermorethe break occurred only inone place and this did notpermitas prompt an extinguishment ofthe arc asis possible Where the circuit is broken simultaneously at two points,for in the latter case the separate arcs 3o are proportionately weakerand hence can be extinguished faster.V Y,

One of the objects of my `invention is the provision of an oil switchwhich is positive and quick acting. This is accomplished byv breakingthel circuit simultaneously at two points by means of a suitable gearactuating mechanism for the movable contacts.

Another object is the provision of a simple .Y contact mechanismy oflight but rugged construction. As previously pointed out. aconstruction'of this sort is essential in order that the inertia of theparts may be a minimum and also that the parts may stand up under themagnetic and mechanical stresses to which they are subjected ywhen theswitch is operated.

In order to acquaint those skilled in the art with the manner ofconstructing and operating my invention, I shall ink connection with theaccompanying drawings describe an embodiment of thesame which isparticularly adaptable for use in a three phase circuit.

In the drawings :l j

'Figure 1 is a vertical section of a switch embodying the inventionshowing one of the terminal insulators and its fittings in section andthe other in elevation; l

Figure 2 is a- :front vertical section of the switch showing the unitsfor one side of a three phase line, in elevation;

Figure 3 is a horizontal section taken o line 3 3 of Figure 1; i

Figure 4 is a horizontal section taken on v line 4-4 of Figure 1 showingin greater detail the arrangement of the contact mechanism; and

Figure 5 is a fragmentary vertical section taken on the line 5 5 ofFigure 3 showing the manner of mounting the separable conf tact means.

The switchshown comprises an oil tight tank 6 having a cover 7. Thecover 7 has a relatively rect-angular groove or recess 8 extendingaround the entire perimeter ofV the bottom side thereof. In the groove8, a strip liner of felt or other'suitable material 9 is snugly'itted topermit of a tight fit between the cover and the rounded edges 10 of thetank 6.

The tank 6 rests on suspension bars 13. These bars are suspended fromthe cover 7 by means of suspension rods 11. which are threaded at bothends. the threaded portions thereof passing respectively through holesin the suspension bars 13 and through holes in the laterally projectinglugs 12 which are integral with the cover 7 and directly in line withthe holes in the hars. B v tightening the nuts 14 and 15, which arefitted to the threaded portions of the rods 11, the tank and cover areheld firmly in position relative to each other. To remove the oil tank,therefore, it is only necessary to take off the nuts 15. This permitsthe suspension bars 13 to be removed and the tank 6 to be lowered out ofits position.

Conductors` provided' at their outer ends with terminal sockets 16 and17, are led through cover 7 by means of suitable insulators 18. Theseconductors terminate within Vfrom the inner the tanlf; v6 in terminals19 and 20, which are integral with them and the two taken together areknown in the art as terminal rods. The base portions of the terminalrods on which the insulators 18 rest, are relatively circular. From thebottom of this circular portion a web extends angularly outwardandterminates in a relatively rectangular base portion. The terminal rodsshould preferably be'east of copper.

In the embodiment shown, the insulators 18, which may be made of anysuitable insulating material, are cemented inv supports or rings 21. Therings 21 are mounted over thve openings 22 in the cover 7. To insure asnug fit between them and the cover 7 a flange 24 projects upward fromeach` opening 22 and fits tightly against agasket fitted into theinnerside of the ring'21. rlhe botton'rsnrfaces of the Vrings 21. rest onaccurately machined surfaces 25 of the cover 7 and are held firmly'against these surfaces by the cap screws 26. At the upper end of eachinsulatory 18 is cemented a metal bushing cap 27 through which thethreaded portions of the terminal rods 19 and 20 arer guided. Nuts 28which fit on upwardly projecting bosses of the bushing caps 27, are usedto secure the terminal rods 19 and 20 in position with relation to theinsulators 18. The nuts 2S are locked in place by lock nuts 29 on whichare mounted the sockets 1G 17v and which arel held in fixed relationthereto by the nuts 30. At the lower portions of the insulators 18, theterminal rods are separated walls thereof by insulatingr bushings B1. n

Integral with and alongl the central portion of the inner side ofthecover 7 are vdownwardly projecting Vlugs 32. These lugs are tapped toreceive machine screws 34 rwhich are used to secure the base firmlyagainst them. The base has a dowuivardly eX- tending portion 83 which isintegral therewith. A central opening is provided iu the extem'liugportion 3? into which the insulator 3671's fitted. and rigidly securedby cement means.

A metal cap 37 fits over and is cemented to the lower end of theinsulator $36. rl`his cap has lugs extending vertically downward fromdiametritarlly opposite sides thereof so that the inner faces of thelugs are relatively parallel to cach other, Between the two innerparallel faces of the extending lugs of the cap 37, gears 38 and 39 arepivotally mounted hy means of pivot pins 40. The gears 38 and Il?) arepreferably made of steel and are accurately cut in order to insure theirsmooth and simultaneous operation. Secured to each side ofthe parallelfaces of the gears 88 and 39 are metal gear plates and 48 which are alsomounted on the pivot pins 40. 'l he gears 38 and 39 are Arigidly securedto their respective gear plates 42 and 43 by means of pins 44 and 45.Since the gears 38 and 39 are .in themselves identical, it is necessaryin order that they mesh properly that one gear be setv on its bar platean angular distance which is equivalent to one gear tooth, This is doneby fixing the gear 38 to its gear plates 42 by ofisetting the holes'through which the pin 44, which firmly holds the gear 3S to its plates,passes an angular distance which is equivalent to that of one geartooth.l

Between the parallel faces of therespeetive gear plates 42 and 43and atends opposite the gears 88 and `39 are mounted the contact blocks 48 bymeansyof pins 41. Contact blocks 48 are preferably made ofcopper and aresecured tothe gear plates by press fits of the ,pins 41 through them andthe gear plates. f y

The arc horns 46 may be cast'of rcopper and consist of 'y hollow Ycent-ral portions through which the gear plates 42 and 45 may be Vfreelyadmitted.V The front vportions are downturned and at the endsfof thesedowny turned portionsiand on the inner sides thereof are projecting'bosses 49. 'lhese are drilled laterally to serve `as bearing surfacesfor the pins 4.7 on which the gear plates 42 and 43 are pivotallymounted. The pins 47 are hield in Aposition by drilling a hole tln'oughYthem and one of the two bosses on each are horn andthen inserting acotter pin through the boss and the pin.

lntegralupright lugs 50 of the are horns v46 are also drilled laterallyto receive the pins 54. Springs 52are connected to these pins'beforethey are pressed into position ing the lugs 50.` The other ends of thesprings 52 pass between the gear )lates 42 andVV 43'respectively and arefastened to pins 55.V The pins 55 are pressed into and have their endsflush-with the outer faces of the gear plates. The purpose of thesprings 52 iste hold'the gear plates 42 and 43 in relatively normalposition with the are horns 46. l l

Contact blocks 48, which are secured to each pair of gear plates 42 and43, are electrically connected with each other by means of a flat,flexible cable 56. rl`his cable is fastened to the lower outer endportions of the contact blocks by means ofthe cap screws 57. It. is alsofastened tothe .bottoni sides of the downward extending portions of theare horns-ttl by the cap screws 58, and then passes upward between therespective pairs of gear plates 42 and 43v and thence over the gears 38and 39 between the downward projecting Vwalls of the cap 37.

To the bottom sides of the angularly disposed rectangular base portionsof the terf minal rods 19 and 20, are secured the brushes by means ofthe cap screws 62. These brushes are preferably made of copper sheetswhich have been soldered togetherat the ends that are secured to theterminal rods.

The ends making contact with. the contact blocks` 48 are accuratelyground yso that good surface Contact is insured between the surface ofthe Contact blocks and the brushes.

Arcing'springs 63 are provided to draw the arc which occurs when thecircuitv is opened and thecontact between the brushes `and the contactblocks 48 is broken.y

These springs are;` made of phosphor bronze and are fastened by means ofthe screws 64 to. the upper sidev of the rectangular base portion .oflthe terminal rods 19 and 20. When the switch brushes 60 and the contactblocks 48 are in contact relation, the circular end portions 53 of `thearc horns 46 rest against the upper end ofthe V at the lower end of thesprings 63. lOn opening the circuit, as 'will be later explained, thesprings 63 and the circular portions 53 are still in contact relationand remain so until the circular portions 53 pass the V bend in thesprings 63 when the circuit is actually broken and the arcs occur.

Since the respective contact mechanisms for each side of the circuit arerelatively identical, it is only necessary since they are both' madeoperable simultaneously bythe gears 38 and 39, to connect actuatingmeansv to only one of them. This is done by securely mounting a pin 65in the gear plates 42.

Pin 65 has its ends extending under and f beyond the are horns 46 topermit the actuating links 66 to be pivotally mounted aty each endthereof. y i

These links are kept in position by cotter pins V61 which are insertedthrough holes in the pins between the links 66 andthe ends of the pins.Links 66 maybe made of fiber or other suitable insulating material whichis capable of withstanding relatively high tensive and compressivestresses. At their upper ends they are pivotally connected to theoperatii'ig arms 68 by means of pivot pins 67 and are heldin position onthe pins by suitable cotter pins 81.

An opera-ting arm 68 is provided for each set of operating links 66. Theoperating arm isL generally cast of malleable iron and is provided atone end with a square opening for the square-operating shaft 70. Alongitudinal slot splits this same end into the split end portions 82and 83. Through the split end portions andrelatively perpendicular tothe slot an opening is provided for admitting the bolt 71 to which isthreaded the nut 72. By tightening this nutthe square opening in the arm68 is firmly clamped to the shaft 70. Integral'lugs 84 and 85 projectingdownward and upward from the operating'arn'l (iS-proper serverespectively as a spring arm and stop arm. To a recess at the lower endof the spring arm 84 the operating spring 69 is connected. The other endof the operating spring 69 is connected to the lug 86 which is castintegral with the cover 7.

vOne end of the shaft 70, is mountedv in a bushing 73. The bushing 7 3is journaled in a bearing 74 which'in turn isffitted into the outwardprojecting portion' 87 of the cover 7. The other end of the shaft passesthrough the bushingr 75 which is j ournaled in the bearing 76. Thisbearing is also fitted'k into an outward projecting portion 88 of thecover 7. The'extended end of the shaft is long enough to permit asuitable setting and trip mechanism 77 for operating the switch to beattached thereto; This maybe of the type which is shown and described inmy copending application, `Serial No. 33,886 tiled June 1, 1925, nowissued as Patent No. 1,672,494 of June 5, 1928.

Pipe means 78 are threaded into the upper part of one side of the oiltank 6 and serve as means through which oil may be poured into the tank.An oil gage 79 is also provided tol indicate the level of the oil in thetank. A plugged nipple 80 for draining the tank `when it is necessary tochange the oil, is

fitted to the tank preferably on the same side with the gage 79 and thepipe fitting 78, but at the lower end thereof so that the bottom of the"nippleis relatively on the same level with the bottom sideof the tanktopermit of complete draining of the tank when necessarv. y

The entire switch may be mounted on pipes which pass through theopenings 90, VThese openings are formed by the semi-circular opening inthe lugs 12 which are integral with the cover 7 and by the semicircularopenings in the clamping means 91 which maybe clamped to the lugs 12 bysuitable bolt means.

To open the circuit in which the switch is used, the operating mechanism77 is tripped. This causes the shaft 7()v to rotate in acounterclockwise direction by virtue of the pull on the spring arm 84 bythe operating spring 69. In the yunit shown in Figure 1, .the oper`ating arm 68 will take the dotted line position 68 and the links 66 willmove into the dotted line position 66.

During the switch closing operation my improved mechanism functions in anovel manner quite superior to the mode of operation of such switches ofthe past with which I am familiar. As the switch is being moved upwardlyto the closed position it moves the arcing horn 46 with it, the horn onthe left hand side of Figure 1 abutting against the arcing spring 63 andflexing the same to the left. As the circular portion 53 of the arcinghorn 46 passes the apex of the V bend of the arcing horn 63 this lastnamed arcing horn is permitted to move back to its original position asshown in the drawings and in moving back it forces the roller 53 of thearcing contact 46 upwardly. This is produced by a snap motion and itcauses the arcing horn 46 to tend to turn about its pivot.

' This is of considerable importance not only in that it produces a snapengagement between' the block 48 and brush 60 but also for the followingreasons: As previously stated, the closing operation of the switch isobtained by the rotation of the shaft 70, said shaft transmitting itsmotion through the operatingr arm 68 and the links 66, This shaft may berotated by any suitable form of switch closingrmechanisin already knownin the art. Such switch closing mechanisms are frequently provided withstop means for limiting' the extent of rotation of the shaft 70 in theswitch closing direction7 said shaft operating` until it abuts againstthe stop means` which stop` means is adjusted in its position so thatabutment therewith is Obtained at the same time that the contact block48 obtains abutment with its contact brush 70. Now, after prolongedoperation of the switching mechanism an appreciable amount of loose playmay develop between the various links and other mechanism extending fromthe contact block 48 to the switch operating mechanism such as themechanism 77 (Figure 2). Vhen the switch operating` mechanism isoperated in a switch closing direction,y under such circumstances theinitial operation thereof will. be effective merely to take up the playbefore it produces any movement of the contact block48. As a result. theswitch operatingjmechanism may reach its limit of motion a slightinterval before the Contact block 48 is moved thereby into fullabutting' relationship with.

the laminated spring 60. If it were not for thcprcsencc of the spring 63then a poor contact would be obtained between the main contact of theswitch. As is` this spring 63 forces the roller 53 upwardly therebyforcing the contact block 48 upwardly through tho action of the spring52. This takes up the free play that may have developed in theconnectingv mechanism and results in the ob taining of a firm pressurecontact between the block 48 and the laminated spring. This is ofparticular importance in switches wherein the contacts have buttingengagement with one another when the switch is closed.

Theabove description is directed prima.- rily to the action of the lefthand contact block 48 shown in Figure 1. With reierence to the rie'hthand contactblock shown in that figure, all of the above functions areobtained and in addition there is this advantage: Suppose that a certainamount of wear has `occurred between the gears 38 and 39 and there is acertain limited amount of free play developed. Under such circumstanceswhen the contact block 48 on the left hand side contact 48 will not havebeen moved into firm abutting engagement with its laminated spring' onthe right hand side of the switch by the action of the links 66 andundersuch conditions the functioningof the spring 63 and the roller 53 on theright hand side of the switch is exceedingly important. This roller 53ias nowridden past the apex of the V formation in the spring 68 andtherefore this springl forces the arcing Contact 46 upwardly. As thisvright handV arcing contact 46 moves upwardly under *the action of thespring` 63, ittends to Vswing .about its pivot 47 thusv stretching' thespring 52 which drawsthe contact 48 upwardly into firm engagement withits laminated spring notithstanding the failure of the links 66 to doso. As a result of this arrangement, a firm Velectrical engagement isobtained between both of the contacts 48 and their respective laminated'springs, thereby insuringr the establishment of a low resistanceswitching circuit.V y This movement of the links 66 causes the `Q'earplates 42 and 43 to be moved downwardly moving the blocks 48 out ofContact with brushes 60. During the first part ofV the opening'operation the rounded elements of horns 46 remain in contact with theupper arms of thel V-shaped elements adj acent the lower ends ofthearcing springs 63. Continued. downward movement of the gear plates 42and 48 places the springs 52 under tension. After the blocks 48 havebeen moved away from brushes 60 a sufficient distance to eliminate anydanger of arcs striking across from the brushes to the blocks, elementspass over the vcrtcxes of the V-elements of springs 63 and the springs52 act to move the horns away from springs 63 with a snap action. Thisserves to produce a quick break and the arcs are quickly drawn inthebath and quenched thereby. This operation will be readily understood byreferring to'Figs. l and 5 of the drawings, the positions of the partsimmediately prior to the break bctwcen'the arcincrv horns and thesprings 68 being` indicated in the latter figure. t will also be notedthat the arcing horns contact with springs 63 before the blocks 48contact with brushes 60. in closing the switch. As the brushes have buttcontact with the blocks, this arrangement is of value as leliminatingarcing between the brush and block with consequentinjury to the switch.The snap action of the horns in the bath is also of importance asquickly drawing the arc in such mannerthat it is readily quenched by thebath before it has any opportunity to build up.

The invention as described has been limited to the details of aparticular embodiment. It is understood that it is not to be limited tothe particular details and embodiment, set forth, as others are*contemplated within the scope of the appended claims. f

I claim:

l. In combinatioma pair of contact blocks spaced relative one another,plates fastened to each side of'said contact blocks, and intermeshingpivotally mounted gears, the opposite ends of said plates being fixed tosaid gears.

2. In combination` a pairofarc horns.

gear plates pivotally mounted between the, inner faces ofv said archorns, contact `blocks` gear plates at oney fastened between said endthereof, cooperating gears fastened be.- tween said gear plates at theother end thereof, and a spring connected to said arc vhorns and saidgear vplates for holding said arc horns and gear plates `11i-relativelynormal posltlon.

3. Inr combination, a centrally mounted member, a bifurcated lug fixedto said member. cooperating gears pivotally mounted between the innerfaces of said lug, gear plates fastened to the fiat faces of said gearsat one end and to contact blocks at the other end` arc horns mountedupon said gear plates and a flexible conducting cable fastened to saidcontact blocks and said arc horns and passing between the inner faces ofsaid lug and above said gears.

4. In combination, an arc horn, a pair of gear plates pivotally-mountedvbetween the inner faces of connecting said arc horn with said gearplates for maintaining said gear plates in relatively normal positionwith said arc horn, a pin fixed in said gear plates, and linkage meanspivotally connected to said pin for actuating said gear plates.

5. In a switch, in combination, a cover, insulators passing therethroughand fixed to said cover, conductor means passing through saidinsulators, lugs integral with the bottom side of said cover and betweensaid insulators, a.. base secured to said lugs, an insulator secured tosaid base, a cap having downward extending lugs securedI to saidvinsulator', gears in cooperative relation pivota ll) mounted betweensaid downward extending lugs, and means connected tosaid gears forcooperating with said conductor means. c

6. In combination, a pair yof' conductor means having base portions,`arcing springs and contact brushes secured to said base portions,circuit closing and opening means mounted between said conductor means,said ineanscomprising a pair of pivotally mount- -ed cooperatinggears,'gear plates secured to gears, contact blocks secured t0 saidlplates for engagement with said brushes, are

said

said arc horn, spring means b c sociated horns pivotally mounted on saidgear plates and engaging with said arcing springs, flexible cablemeansinterconnecting said contact blocks, and linkagemeanspivota-lly'connected tothe gear plates secured to oneof-said gears tomake or'break said electric circuit by actuating said gears causing saidcontact blocks and arc horns to make or break contact with said contactbrushes and arcing springs respectively. f

7. In combination, a cover, a shaft journ'aled in said cover, anoperating arm clamped to said shaft, switch mechanism operated by saidarm, said opera-ting armhaving lugs integral-therewith projectingdownward and upward respectively, an operating spring attached to one ofsaid lugs and to said cover, said spring urging the arm 1n switchopening direction, and l'means cooperating with' the other lug to 'limitopening movement of the arm, the shaftbeing releasably held in switchclosing position.

8,"1In a switch, the combination of a pair of -terminalrods havingenlarged base' portions, a. paircof'brnshes fastened `to the bot'- tomsides of said baseportions, a pair of lpivotally mounted cooperatinggears, gear plates secured to saidv gears, contact blocks securedto'said gear-plates and adapted to contact with said brushes, andlinkage mea-ns for simultaneously swinging said blocks into and out ofcontact with said brushes.

9. In a switch, the combination of va pair of terminal rods, A. brushesfastened to the lower ends of said rods, arcing springs fastened to saidrods opposite said brushes, contact blocks adapted' for contact withsaid rushes, archorns adapted for Contact with said are springs, gearplates fastened to said contact blocks and having a "air of ,pivotedcooperating gears pivoted t vcreto at their` adjacent ends, and meansformoving one set of the gear plates about the axis of their asgear forvswinging said contact blocks and arc horns about saidgears into f andout of contact lwithsaid brushes and arc springs, respectively.

10. In a switch, the combination of arc horns, a pair of contact blocks,pivoted gear plates fastened to said contact blocks, intermeshing gearssecured to said plates, and resilient means fastened to said arc hornsandsaid gear plates for holding said hornsfin 'normal position withrespect to said plates.

11. vIn aswitcluthe combination of a tank, a cover for said tank, a airof insulator conductor means leading t rough said cover, afixedfinsulating member intermediate said` conductor means,a pair ofcooperating gea!" membersfpivotally mounted on said/insulatllO of a paire ing member, brushes secured to the lower means' connecting saidcontact blocksV with lao thm

said gears, and meanspivotally connected to one of said connectingmea-ns same about the aXis of its associated gear for swinging saidcontact 12. An electric switchV including contact means, a pair ofswitch arms movable into and out of butt ,contact with thek contactmeans, means ioractuating one of said switch arms to the switch closedposition, a driving connection extending from `said one switch arm tothe other for actuating said other arm,

and means associated with said contactineans said other contact armwould not otherwise reach its full closed position when the contact armthat is actuated is in full abutment with the contact means. i Y A 13.An electric .switch including contact means, a pair of switch armsmovable into and out` of butt Contact therewith,`common actuating meansfor vthe switch arms, said actuating means being limited in its motionby the abutment of either one ot switch arms with the contactmeans, andmeans with at least one of the switch arms and the contact means formoving said one switch arni into engagement with, the contact meansindependently ci the actuating means after said one switch arm has beenlmoved into proximity ot the contact means, 'whereby said f one arm`firmly engages the .contact means even though loose' play shoulddevelopin the driving connection to said one switch arm to prevent said one armreaching firm engageinent withA the contact means under the action oithe actuating means due to the previous abutment of said other-armragainst Vthe contact means. l V141. An electric switch including a maincontact, a-switch arm movable into butt ,contactl therewith actuatingnieansfor actuating the switch arm, and arcingcontacts associated withthe main Contact and with the switch arm for engaging one another priorto the engagement of the switch arm with the main contact, said arcingcontacts including means effective after a predetermined engagingmovement thereof and prior to the engagemen of the switch arm with vthemain contact Y for ,moving the switch armtoward the main contactindependently lof the switch actuating means, whereby firm electricalcontact isobtainedy between the kswitch arm and the inanicontact inthe'even-t that the switcharni for moving they blocks into and out ofv.contact with said brushes about `the pivotal mountings osaidcooperating gears.

associated vincomes he same approachesitsV full closed position.V

16. An electric switch vincluding a main contact, aswitch arm movableinto butt contact therewith, actuating meansfifor actuating the switcharm, and arcing contacts associated with vthe main contact and-with theswitch arm for engaging one another priorto the engagement ofthe switcharinwith the main contact, said arcing contacts including means forsnapping abutment with the main contact.

ln witness whereof, I yhereunto subscribe my name this` 26th day ofNovember, 1924-.

' o ALFRED F. C. LOTZ.

is not in the `full closed position when'ther j the contact larm into

